Computer Methods in Materials Science
Loading...
ISSN 2720-4081
e-ISSN: 2720-3948
Issue Date
2021
Volume
Vol. 21
Number
No 2
Description
Journal Volume
Computer Methods in Materials Science
Vol. 21 (2021)
Projects
Pages
Articles
Optimization of material distribution for forged automotive components using hybrid optimization techniques
(Wydawnictwa AGH, 2021) Sebastjan, Przemysław; Kuś, Wacław
The paper deals with the problem of optimal material distribution inside the provided design area. Optimization based on deterministic and stochastic algorithms is used to obtain the best result on the basis of the proposed objective function and constraints. The optimization of the shock absorber is used as an example of the described methods. One of the main difficulties addressed is the manufacturability of the optimized part intended for the forging process. Additionally, nonlinear buckling simulation with the use of the finite element method is used to solve the misuse case of shock absorber compression, where the shape of the optimized part has a key role in the total strength of the automotive damper. All of that, together with the required design precision, creates the nontrivial constrained optimization problem solved using the parametric, implicit geometry representation and a combination of stochastic and deterministic algorithms used with parallel design processing. Two methods of optimization are examined and compared in terms of the total amount of function calls, final design mass, and feasibility of the resultant design. Also, the amount of parameters used for the implicit geometry representation is greatly reduced compared to existing schemes presented in the literature. The problem addressed in this article is strongly inspired by the actual industrial example of the mass minimization process, but it is more focused on the actual manufacturability of the resultant component and admissible solving time. Commercially accessible software combined with authors' procedures is used to resolve the material distribution task, which makes the proposed method universal and easily adapted to other fields of the optimization of mechanical elements.
An evaluation of the mechanical properties of 13MnSiCr7 steel by digital image correlation
(Wydawnictwa AGH, 2021) Kempny, Marcin; Rozmus, Radosław
"In this paper, the possibility of replacing tensile extensometers with a non-contacting device for measuring elongation has been analyzed. An example of a non-contacting device is a Digital Image Correlation System (DIC). Such systems are widely used in various areas, for example, biology or modern engineering. DIC systems have several advantages that seem to be promising for testing modern materials. The most important is the fact that there is no physical contact between the sample and the DIC and therefore no additional force is applied during the experiment. On the other hand, a lack of contact with the sample can cause large measurement inaccuracies. Another advantage would be that a DIC can measure strain on the whole surface of the sample in all directions, instead of measuring part of the surface in one direction like in other extensometers. Because of these abilities, the environment impact on test bench (DIC + load device), and differences between conducted experiment with normalized tensile test needed to be investigated. The testing machine was replaced by a DIC system cooperating with a tension-compression module. The proposed method was used to monitor and record the images to determine the basic properties of 13MnSiCr7 grade steel. Twelve tests were performed. The analysis was done by comparing the values of mechanical properties obtained in a static tensile test, such as yield strength, tensile strength, Young's modulus, elongation of the material"," with the values of these properties determined experimentally. For each sample, stress-strain curves were evaluated. To check if the results were correct, a Q-Dixon test was performed in each case, confidence intervals were also calculated. Finally, the obtained properties were compared with those from the standard tensile test acquired from the manufacturer's material card."
Artificial intelligence approach for detecting material deterioration in hybrid building constructions
(Wydawnictwa AGH, 2021) Česnokov, Andrej Vladimirovič; Mihajlov, Vitalij Vital?evič; Dolmatov, Ivan Viktorovič
Hybrid constructions include heterogeneous materials with different behaviors under load. The aim is to achieve a so-called synergistic effect when the advantages of particular structural elements complement each other in a unified system. The building constructions considered in the research include high-strength steel cables, fiberglass rods, and flexible polymer membranes. The membrane is attached to the rods which have been elastically bent from the initially straight shape into an arch-like form. Structural materials inevitably deteriorate during a long operational period. The present study focuses on detecting material deterioration using Artificial Neural Networks (ANNs), which belong to the scope of intelligent techniques for data analysis. Appropriate ANN structures and required features are proposed. A semi-supervised learning strategy is used. The approach allows the training of the networks with normal data only derived from the construction without defects. Material degradationis detected by the level of reconstruction error produced by the network given the input data. The work contributes to the field of structural health monitoring of hybrid building constructions. It provides the opportunity to detect material deterioration given the forces in particular structural elements.
A new BEM for modeling and simulation of 3T MDD laser-generated ultrasound stress waves in FGA smart materials
(Wydawnictwa AGH, 2021) Fahmy, Mohamed Abdelsabour
The goal of this study is to present a new theory known as the three-temperature memory-dependent derivative (MDD) of ultrasound stress waves in functionally graded anisotropic (FGA) smart materials. It is extremely difficult to address the difficulties related to this theory analytically due to its severe nonlinearity. As a result, we suggest a new boundary element method (BEM) to solve such equations. The suggested BEM technique incorporates the benefits of both continuous and discrete descriptions. The numerical results are visually represented to demonstrate the impacts of MDD three temperatures and anisotropy on the ultrasound stress waves in FGA smart materials. The numerical findings verify the proposed methodology's validity and accuracy. We may conclude that the offered results are useful for comprehending the FGA smart materials. As a result, our findings contribute to the advancement of the industrial applications of FGA smart materials.
On the prognosis of the growth of a heterostructure from a gas phase to analyze the possibility of decreasing mismatch-induced stresses
(Wydawnictwa AGH, 2021) Pankratov, Evgenij Leonidovič
An approach to decreasing mismatch-induced stress in a heterostructure by radiation processing during growth from the gas phase is introduced in this paper. Within the framework of the approach with decreasing mismatch-induced stresses, one can find the acceleration of the recombination and diffusion of radiation defects generated during radiation processing. An analytical approach for analyzing mass and heat transfer is also introduced. The approach provides the opportunity to simultaneously take into account spatial and temporal variations of mass transfer parameters. At the same time, the approach allows the nonlinearity of the considered processes to be taken into account.